The performance of the Sempron 3500+(1.8GHz, 512K cache) should be equivalent to the Turion64 ML 32(1.8GHz, 512K cache) considering they share the same architecture. Only difference between the two is that the Sempron 3500+ is capable of supporting the newer DDR2 memory. With that in mind search the web for reviews for the Turion64 ML 32 and from my experience the performance with a Pentium M 1.7GHz will be very similar.
Here's a review which might help...http://www.hardwarezone.com/ar...iew....cid=14&pg=7
HP Pavilion TX2500..AMD Turion X2 Ultra ZM-86, 3GB DDR2 800, 320GB 5400rpm SATA, ATi Radeon HD3200/M780G.